The degradation study of PVC/ABS and PVC/ABS/Carbon blends during repeated extrusion on mechanical and thermal properties.
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
Faculty of Manufacturing Engineering
THE DEGRADATION STUDY OF PVC/ABS AND
PVC/ABS/CARBON BLENDS DURING REPEATED EXTRUSION
ON MECHANICAL AND THERMAL PROPERTIES
Muhyiaddin Abdul Qadir bin Abu Bakar
Master of Manufacturing Engineering (Industrial Engineering)
2014
© Universiti Teknikal Malaysia Melaka
ｐｖｃＯａｂｓｒｏｾ＠
THE DEGRADATION STUDY OF PVC/ABS ａｾｄ＠
BLENDS DURING REPEATED ｅｘｔｒｌＧｓｉｏｾ＠
ON MECHANICAL AND THER'1AL PROPERTIES
MUHYIADDIN ABDUL QADIR BIN ABL' BAKAR
A thesis submitted
in fulfillment of the requirements for the degree of Master of
Manufacturing Engineering (Industrial Engineering)
Faculty of Manufacturing Engineering
UNIVERSITI TEKNIKAL MALAYSIA :WELAKA
2014
© Universiti Teknikal Malaysia Melaka
DECLARATION
I hereby, declared that this report entitled ' The Degradation Study of PVC/ABS and
PVC/ABS/Carbon Blends During Repeated Extrusion on Mechanical and Thennal Properties'
is the results of my own research except as cited in the references.
0
Signature
Name
: Muhyiaddin Abdul Qadir Bin Abu Bakar
Date
© Universiti Teknikal Malaysia Melaka
APPROVAL
I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms
of scope and quality for the award of Master of Manufacturing Engineering (Industrial
Engineering).
Signature
Supervisor Name
: Dr. Zaleha Binti Mustafa
Date
© Universiti Teknikal Malaysia Melaka
ABSTRACT
The degradation effects on numbers of extrusion of PVC/ABS and PVC/ABS/Carbon
blends to mechanical and thermal properties have been investigated. The composition of
PVC/ ABS blends was 80/20 wt% and PVC/ABS/Carbon was 73/23/7 wt°/o. The study has
been focused on ultimate tensile strength, strain at ultimate tensile, elastic modulus and
strain at faiJure for mechanical properties of the blends. Ultimate tensile strength, strain at
ultimate tensile and elastic modulus have been retained by both PVC blends due to the
presence of SAN phase from ABS that possess the complete retention with increasing
numbers of extrusion. On the other hand, the presence of butadiene rubber (BR) phase in
ABS increase the deformability of PVC blends which contributed to increase strain at
failure. Increased numbers of extrusion have refined the dispersion of carbon in the blends
and made stronger adhesion between carbon and the matrix that led to increase the strain at
failure of PVC/ABS/Carbon. Glass transition temperature (Tg) have been obtained using
differential scanning calorimetry (DSC) for thermal properties of the blends. The partial
miscibility between the components of the blends was concluded from two Tg obtained
from DSC test. Finally, a morphological study of the fracture surface has been completed
using scanning electron microscopy (SEM). The images from SEM justify the mechanical
properties of the PVC blends.
© Universiti Teknikal Malaysia Melaka
ABSTRAK
Satu kajian berkaitan kesan proses penolakan berterusan keatas campuran PVC/ABS dan
PVCIABS/Karbon telah dijalankan bagi melihat perubahan keatas sifat mekanikal dan
termal campuran. Komposisi bagi campuran PVC/ABS telah ditetapkan pada 80120 % dan
campuran PVC/ABS/Karban pada 7312317 %. Kajian ini akan memberi penekanan pada
kekuatan tegangan puncak, terikan pada tegangan puncak, modulus anjal dan terikan
putus bahan. Kekuatan tegangan puncak, terikan pada tegangan puncak dan modulus
anjal dapat dikekalkan oleh kedua-dua campuran berpunca daripada kehadiran fasa SAN
daripada ABS yang telah menghalang daripada berlakunya perubahan pada sifat bahan
walaupun proses penolakan berterusan dilakukan berulang kali. Sela in itu, kehadiran fasa
getah butadiene (BR) dalam ABS telah meningkatkan kadar perubahan bentuk bahan
campuran PVC yang secara tidak langsung telah meningkatkan sifat terikan putus.
Penambahan proses penolakan berterusan telah mensebatikan unsur karbon dalam
campuran PVC yang menyebabkan lekatan antara unsur karbon dan unsur matrix
bertambah baik. Keadaan ini menyebabkan peningkatan pada sifat terikan putus bahan
campuran PVC. Suhu perubahan gelas (Ig) telah direkodkan menggunakan mesin
pengimbas perubahan kalori (DSC) untuk sifat termal bahan campuran. Dua Tg telah
didapati pada setiap sampel yang mana telah menunjukkan bahawa bahan campuran PVC
ini adalah bersifat separuh terlarut campur.. Bagi mengesahkan sifat mekanikal bahan
yang telah diperolehi tadi, maka akhirnya ujian pengimbasan electron mikroskop (SEM)
telah dijalankan.
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ACKNOWLEDGEMENTS
First and foremost, I would like to take this opportunity to express my sincere
acknowledgement to my supervisor Dr. Zaleha Mustafa from the Faculty of Manufacturing
Engineering Universiti Teknikal Malaysia Melaka (UTeM) for her essential supervision,
support and encouragement towards the completion of this Master Project 2.
Particularly, I would also like to express my deepest gratitude to Mr. Azhar and Mr. Hairul
Hisham, the technicians from material laboratory Faculty of Manufacturing Engineering,
for their assistance and efforts in the lab and analysis works.
Special thanks to all my peers, my mother, beloved father and siblings for their moral
support in completing this Master Project 2. Lastly, thank you to everyone whom had been
to the crucial parts of realization of this project.
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TABLE OF CONTENTS
CHAPTER
TITLE
DECLARATION
ABSTRACT
ABSTRAK
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
LIST OF ABBREVEATIONS
LIST OF APPENDICES
1
2
3
INTRODUCTION
1.1 Background
1.2 Problem Statements
1.3 Research Objectives
1.4 Scope of study
LITERATURE REVIEW
2.1
Thermoplastics and thermosets
2.2
Polymer Degradation
2.2.1 Thermal Degradation
2.2.2 Photo-degradation
2.2.3 Oxidation or aging degradation
2.3
Polyvinyl Chloride (PVC)
2.3.1 Mechanical Properties
2.3.2 Thermal Properties
2.3.3 Advantages and Disadvantages
2.3.4 Rigid PVC for Extrusion
2.4
Acrylonitrile Butadiene Styrene (ABS)
2.4.1 Properties
2.4.2 Mechanical Properties
2.4.3 Thermal Properties
2.4.4 Ultraviolet Resistance
2.4.5 Preheating and Pre-drying
2.4.6 Advantages and Disadvantages
2.5
Polymer Blends
2.5.1 PVC/PS and PVC/ABS Blends
2.6
Carbon
2.7
Extrusion Process
2.7.1 Process Parameters
2.8
Repeated Extrusion
2.9
Fracture Morphology of Amorphous Polymer
2.10 Design of Experiments (DOE)
2.11 Summary
METHODOLOGY
3.1
Introduction
3.2
Design of Experiments (DOE)
3.3
Flow Chart
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iv
vi
vii
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xv
1
3
7
7
9
9
10
11
13
15
16
19
21
22
23
24
25
27
28
29
29
31
31
37
39
39
41
47
51
53
54
54
56
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4
5
Materials
Blends Preparation
Extrusion Process
Samples Preparation
Mechanical Properties
Thermal Properties
Morphology
RESULT AND DISCUSSION
4.1
Introduction
4.2
Mechanical Properties
4.2.1 Analysis of variance (ANOVA)
4.2.2 Ultimate Tensile Strength
4.2.3 Strain at Ultimate Tensile Strength
4.2.4 Elastic Modulus
4.2.5 Strain at Failure
4.3
Thermal properties
4.4
Fracture Morphology
CONCLUSION & RECOMMENDATION
5.1
Conclusion
5.2
Recommendation
REFERENCES
APPENDICES
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58
58
60
61
63
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68
71
73
74
75
77
81
91
93
94
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LIST OFT ABLES
TITLE
TABLE
PAGE
2.1
Mechanical & thermal properties of PVC
18
3.1
Design of experiment (DOE)
55
3.2
Properties of PVC
57
3.3
Properties of ABS
57
3.4
Properties of Carbon
57
3.5
Blend composition
58
3.6
Temperature zones of extrusion profile
58
3.7
Numbers of specimens required
60
Specification of Universal Testing Machine 5kN (Computer Servo
62
3.8
Control)
3.9
Zeiss Stemi 2000 Stereomicroscope specification
65
3.10
Zeiss EVO 50 XVP Electron scanning microscope specification
65
Effect of numbers of extrusion to the mechanical properties of PVC
67
4.1
4.2
and PVC blends
Effect of numbers of extrusion to the glass transition temperature of
77
PVC, ABS and PVC blends
4.3
Composition of PVC and ABS at PVC and SAN-rich phase
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80
LIST OF FIGURES
FIGURE
2.l
TITLE
Thermal dehydrochlorination of PVC. C: Carbon. H: Hydrogen. Cl :
Chlorine.
2.2
ｾＺ＠
PAGE
11
Heat. x,y: Integers
Scanning Electron Micrograph for (a)-(i) unexposed film of only
12
PVC (a)-(ii) only PVC film exposed to solar radiation (a)-(iii) only
PVC film exposed to artificial UV radiation. (b)-(i) Unexposed
composite film of PVC- ZnO (b)-(ii) PVC- ZnO composite film
exposed to solar radiation (b)-(iii) PVC- ZnO composite film exposed
to artificial UV radiation
2.3
Laser microscopic image of the fading section around the surface
13
after weathering test: (a) 0 h (the obvious inorganic particles are
pointed by arrows), and (b) 3000 h (the obvious voids are pointed by
arrows)
2.4
Laser microscopic image of the section around the surface after
14
thermal aging test: (a) 0 h, and (b) 240 h. The obvious inorganic
particles are pointed by arrows
2.5
Molecular structure for (a) vinyl chloride and (b) polyvinyl chloride,
15
PVC
2.6
Dependence of tensile strength (crM) of the extrudate obtained from
17
the mixture of A/B (0 % gel/I 00% gel) granulated products on the
processing temperature (T): 1- 0/ 100 % gel; 2- 25/75 % gel; 3- 50/50
% gel; 4- 75/25 % gel; 5- 100/0 % gel
2.7
Dependence of relative elongation at failure (c8 ) of the extrudate
17
obtained from the mixture of A/B (0% gel/ 100% gel) granulated
products on the processing temperature (T): 1- 0/100 % gel; 2- 25/75
% gel; 3- 50/50 % gel; 4- 75/25 % gel; 5- 100/0 % gel
2.8
DSC Curve of uPVC Gelation Test
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20
2.9
Molecular structure of ABS monomer
23
2.10
Molecular structure of ABS
24
2.11
The change in Izod impact strength with the increase of injection
25
cycles
2.12
The change in stress at yield point with the increase of injection
26
cycles
2.13
External surface of ABS sewer pipe after UV exposure
28
2.14
Notched impact strength of composites as a function of nano-CaC03
33
content
2.15
Yield strength and elongation at failure of the composites as a
33
function of nano-CaC0 3 content
2.16
Impact strength as a function of the PVC:ABS ratio
34
2.17
Impact properties of the PVC/ ABS blends at various mass blending
35
ratios
2.18
Scanning electron micrographs of tensile-tested PVC/ ABS (70:30)
36
blend
2.19
TE M images; left=l5nm CB sample " good dispersion"; right= l5nm
37
CB sample " bad dispersion"
2.20
The relation between the Modulus of elasticity of HDPE sample with
38
weight fraction of Ti02-C.B.fillers at different wt.% of C.B and
constant Ti02 content (15% wt) and. at different wt.% of Ti02and
constant C.B content
2.21
Mass throughput at screw speeds of 50 and 90 rpm and Energy
40
consumption at screw speeds of 50 and 90 rpm
2.22
The extrusion pressure and elongation at failure, as a function of
41
number of extrusions
2.23
The elongation at failure for ABS vs the number of cycles in the
extrusion series, the series involving ageing steps of 72 h at 90°C and
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42
the combined extrusion and ageing series. The data point at 0 cycles
represent elongation at failure for samples of ABS after the first
extrusion
2.24
Tensile strength of ABS subjected to multiple reprocessing
44
2.25
The effect of the number of injection mouldings of ABS on tensile
44
strength (1) and tensile stress at failure (2)
2.26
Elongation at failure of ABS subjected to multiple reprocessing
45
2.27
The effect of the number of injection mouldings of ABS on tensile
45
strain at ultimate tensile (1) and tensile strain at failure (2)
2.28
The effect of the number of injection mouldings of ABS on modulus
46
of elasticity
2.29
The effect of the number of injection mouldings of PC on tensile
46
strength (I) and tensile stress at failure (2)
2.30
Fracture surface of PS in SEM: a, overview with brittle fracture
48
edges; b, larger magnification of ruptured crazes with domain-like
hills, revealing broken and relaxed craze fibrils
2.31
Scheme
showing
differences
between
homogeneous
(a)
and
48
fibrillated crazes (b) in relation to the entanglement network: top,
view as in electron micrographs; bottom, entanglement network with
stretched meshes. a, Dense pattern of small stretched meshes in
homogeneous crazes; b, coarse pattern with voiding and fibrillation in
large meshes in fibrillated crazes
2.32
SEM micrographs of ABS in shear deformation fracture level
49
2.33
Shear deformation of 100 wt% ABS
50
2.34
'Black Box' Process Model Schematic
51
2.35
Half-Normal Probability Plot
52
2.36
Normal Probability Plot
52
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3.1
Design schematic for DOE of the study
55
3.2
Flow chart of the experiments
56
3.3
ASTM D638-I-mm units
60
3.4
GOTECH Universal Testing Machine
61
3.5
Perkin Elmer DSC 4000
63
3.6
Zeiss Stemi 2000 Stereomicroscope
64
3.7
Zeiss EVO 50 XVP Scanning Electron Microscope
65
4.1
Half normal% probability graph; (a) Ultimate tensile
ｳｴｲ･ｮｧｨ
ｾ＠
(b)
69
Strain at ultimate tensile, (c) Elastic Modulus, (d) Strain at failure
4.2
Normal probability plot ofresidual; (a) Ultimate tensile
ｳｴｲ･ｮｾ＠
(b)
70
Strain at Ultimate Tensile, (c) Elastic Modulus, (d) Strain at failure
4.3
Interaction plot between materials and number of extrusion; effect of
72
numbers of extrusion to ultimate tensile strength.
4.4
Interaction plot between materials and number of extrusion; effect of
73
numbers of extrusion to strain at ultimate tensile
4.5
Interaction plot between materials and number of extrusion; effect of
74
numbers of extrusion to elastic modulus.
4.6
Interaction plot between materials and number of extrusion; (a) effect
75
of different materials to strain at failure, (b) effect of number of
extrusions to strain at failure.
4.7
DSC thermograms of PVC with different numbers of extrusion
78
4.8
DSC thermograms of PVC/ABS 70/30 wt°/o with different numbers
78
of extrusion
4.9
DSC thennograms of PVC/ABS/Carbon 70/23/7 wt°/o with different
79
numbers of extrusion
4.10
Optical and Scanning electron micrographs of tensile tested 1st
81
extrusion PVC (a) PVC drawing at the crack path;(b) pores at the
crack ;(c) --{d) crack path propagation
4.11
Scanning electron micrographs of tensile tested 2°d extrusion PVC.
(a) optical micrograph on the start of crack formation path;(b) jagged
82
fracture surface;(c)-(d) smooth fracture surface.
4.12
Scanning electron micrographs of tensile tested 3rd extrusion PVC.
(a) shear deformation region;(b)-(c) fibrillated deformation region;(d)
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83
crack path propagation.
4.13
Scanning electron micrographs of tensile tested
wt% PVC/ABS blend.
1 st
extrusion 70/30
(a) jelly fish surface;(b)
84
coexisted
deformation;(c) crack from the top view; (d) crack from side view
4.14
Scanning electron micrographs of tensile tested 2°d extrusion 70/30
wt% PVC/ABS
85
blend. (a) microvoids on shear deformation
surface;(b) coexisted deformation;( c) shear deformation region; (d)
fibril from side view
4.15
Scanning electron micrographs of tensile tested 3rd extrusion 70/30
86
wt% PVC/ABS blend. (a) fibrillated deformation surface;(b) -{c)
shear deformation or homogeneous region;( d) crack from side view
4.16
Scanning electron micrographs of tensile tested
1 st
extrusion 70/23/7
87
wt% PVC/ABS/Carbon blend. (a) shear deformation surface;(b)
relaxed craze fibril ;(c) not homogeneous dispersion of carbon;(d)
crack at with massive shear deformation
4.17
Tensile fracture surface of 70/23/7 wt% PVC/ABS/Carbon blends
88
after 2rd extrusion. (a) shear or homogeneous deformation surface;(b)
coexisted deformation surface;(c) fibrillated deformation surface;(d)
dispersion of carbon
4.18
Tensile fracture surface of 70/23/7 wt% PVC/ ABS/Carbon blend
after 3rd cycle of extrusion process.(a) brittle region (b) homogeneous
region, (c) crack, (d) more refine dispersion of carbon.
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89
LIST OF ABBREVEATIONS
ABS
Acrylonitrile butadiene styrene
ASA
Acrylonitrile Styrene Acrylate
AMS-ABS
a-methylstyrene-acrylonitrile- butadiene-styrene copolymer
ANOVA
Analysis of Variances
ASTM
American Society for Testing and Materials
V-0
Burning stops within 60 seconds on a vertical specimen
BR
Butadiene rubber
DOE
Design of Experiments
CaC03
Calcium carbonate
CB
Carbon black
oc
Degree of centigrade
DSC
Differential scanning calorimetry
OMA
Dynamic Mechanical Analysis
CPE
Chlorinated polyethylene
Elongation at failure
EVA
Ethylene vinyl acetate
EPDM
Ethylene propylene diene monomer
ft
Foot
GPC
Gel permeation chromatography
Tg
Glass transition temperature
HCI
Hydrogen chloride
HDT
Heat distortion temperature
HOPE
High-density polyethylene
h
hour
in
Inch
J
Joule
kg
Kilogram
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LDPE
Low density polyethylene
LOI
Loss on ignition
MAH
Maleic anhydride grafted
MAStVA
Maleic anhydride-styrene-vinyl acetate
Wt%
Mass fraction
m
Meter
Tm
Melting temperature
mm
Milimeter
MPa
Megapascal
NBR
Nitrile butadiene rubber
Tonset,m
Onset melting temperature
%
Percent
PC
Polycarbonate
PMMA
Poly(methyl methacrylate)
pp
Polypropylene
PPE
Polyphenyl ethers
PVC
Polyvinyl chloride
PS
Polystyrene
lbs
Pound
psi
pound per square inch
RH
Relative humidity
rpm
Revolutions per minute
T
Temperature
CTM
Tensile strength
Ti02
Titanium dioxide
K-value
Thermal conductivity
TGA
Thermogravimetric
TP
Thermoplastic
TS
Thermo set
TEM
Transmission electron microscopy
SEM
Scanning electron microscope
SD
Standard deviation
SAN
Styrene Acrylonitrile
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SMA
Styrene-maleic anhydride
UL94
Standard for Safety of Flammability of Plastic Materials
UV
Ultraviolet
VCM
Vinyl Chloride Monomer
XRF
X-ray Fluorescence
w
Weight fraction
ZnO
Zinc Oxide
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LIST OF APPENDICES
TITLE
NO
A
Page
104
Overall ANOV A Report
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CHAPTER!
INTRODUCTION
1.1
Background
Plastics can be divided into two groups which are thermoplastic (TP) and thermoset
(TS). Thermoplastic is the type of plastic that can be repeatedly softened by heating and
then solidified by cooling. Molecules
iri
a thermoplastic are held together by relatively
weak intermolecular forces. Thermoplastic can be processed several times and makes these
kinds of plastics suitable for recycling. Thermosets in a soft solid or viscous state that
changes irreversibly into an infusible, insoluble polymer network by curing. Curing can be
induced by the action of heat or suitable radiation or both. A cured thermosetting polymer
is called a thermoset.
Polyvinyl chloride (PVC) is a thermoplastic polymer. PVC is primarily an
amorphous material with good durability, fire retardant, oil and chemical resistant and
good mechanical properties. Many commercial polyvinyl chloride (PVC) resins contain
crystalline regions ranging from 5 to I 0 % of the polymer. The polymer will remain intact
at temperatures well over 200 °C. The region of crystallinity with relatively narrow
molecular weight distribution will help impart superior melt strength during extrusion.
Another unique characteristic of polyvinyl chloride (PVC) is the amorphous nature of the
polymer promotes cost effective fabrication of clear articles in thickness exceeding 0.25 in
(lOmm) if proper addictive selection used (Grossman, 2008).
Polyvinyl chloride (PVC) contains approximately 57 % chlorine by weight. The
condition of the polymer will creates strongly polar region and make it compatible with a
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wide range of additives. No other commercial polymer can have its properties modified in
so many ways compare to polyvinyl chloride (PVC). Beside of that, the chlorine in
polyvinyl chloride (PVC) will also make the polymer flame resistance.
PVC has been use in wide range of short life and long life product application. In
short life product, PVC have been processed in packaging material use in food, cleansing
materials, textile, beverage packaging bottles and medical devices. In long life product,
PVC have been processes into pipes, window frames, cable insulation, floors coverings
and roofing sheets (Sadat-Shojai and Bakhshandeh, 2011).
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1.2
Problem Statements
Every product has specific cycle time. There is a time when the product will come
to their end life and the product need to be properly disposed. PVC with a wide range of
products, their waste will increase with time. Thus will become a problem to the
community. Today, PVC waste is dispose in landfill. However, using landfill to cater the
problem is not a good solution because the area required for landfilling will increase with
increasing of the waste. Beside of that, using landfilling to dispose PVC waste have
potential environmental hazard because of the chlorine content of the polymer.
Another route to solve the increment of PVC waste is by recycle the PVC waste
into another product. Thus, recycling of the PVC has gain interest for researcher in order to
produce secondary materials (Sadat-Shojai and Bakhshandeh, 2011). However, recycle the
PVC into similar or another product is not a straight path. Recycle PVC showed to have
inferior mechanical properties (Yarahmadi et al., 2001). The recycle PVC with low
mechanical properties however can be process into a low strength requirement type of
product with cost conscious production. But, if the recycle PVC need to be use in another
requirement type of products, the molecule properties of the material need to be alter.
One of the most popular methods to retain and increase the properties of the
material is by blending the polymer with another polymer. Polymer blending has become
an important field in polymer research. ln this research the target was to reduce the
polymer waste problem by blending the PVC with other type of polymer and make sure
that the recycle blends polymer still retains an identical properties compare to the first
cycle of the blends. With identical properties of the blends compare to the virgin and the
recycle of the virgin, it will make the blends as an ideal replacement material to be used for
consumer products. Then, by showing a slightly decrease in properties after a few recycle
compare to the copolymer that show greater decrease in properties, the polymers blends
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will fulfil the purpose to retain the properties of the material and can be used for several
times in processing. It will give a huge profit for recycle industries because the scrap from
the blends can be recycle to be made into the same or different product that meet the
requirement base on their properties whereas the recycle from the copolymer cannot
sustain the same properties.
Beside of improving physical properties of the material, polymer blends will also
benefit in low investment cost in a new material design. In this case, a cheaper material
like PVC will be dilute with expensive polymer material in hope to retaining some of the
high performance properties. The blends maybe homogeneous (true thermodynamic
miscibility of components) or heterogeneous (phase-separated). In heterogeneous blends,
components maybe thermodynamically immiscible but mechanically compatible (Elias,
2003). Many researches have blend PVC with other polymer materials such as
PVC/PMMA, PVC/NBR, PVC/EVA and PVC/CPE (Grossman, 2008). Thus, the objective
to minimize the cost for a new material design with improves material properties can be
achieved.
Polystyrene (PS) is amorphous region material with good impact resistance high
heat resistance. In theory, blending PVC with PS will improve thermal and mechanical
properties of the material. But, does the properties can be retain if the blends were recycles
for several times? The assumption can be made that the recycle of PVC/PS blends will
give the identical outcome with slightly reduce number compare to the first cycle. Another
famous amorphous region material is acrylonitrile butadiene styrene (ABS) with good
impact resistance, toughness and weather ability. In theory, blends PVC with ABS will
improve impact resistance, toughness and weather ability of the material (Rimdusit et al. ,
2012). But, does the properties can be retain if the blends were recycles for several times?
Same as PVC/PS blends, assumption can be made that the recycle of PVC/ABS blends will
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give the identical outcome with slightly reduce number compare to the first cycle. There
are very limited knowledge about the properties either PVC/PS or PVC/ABS biends when
there were recycles for several times.
Blends of polyvinyl chloride (PVC) with a-methylstyrene-acrylonitrile- butadienestyrene copolymer (AMS-ABS) show a single glass transition temperature (Tg) when
observed by differential scanning calorimetry (DSC). This result indicates that PVC is
miscible with AMS-ABS (Zhang et al. , 2013). The research suggest that the most
interesting area for further investigation is the region containing 15 - 30 wt% of AMSABS because within these compositions, the heat distortion temperature (HDT) and the
impact strength have improved effectively without losses in tensile and flexural properties.
The impact strength show gradually increase when the PVC/ABS blends below 30 wt% of
ABS content and the drastic increase observed when the ABS content range from 30 to 50
wt% (Rimdusit et al. , 2012). Pavan et al. (1980) show that 30 wt% of PVC/ABS blends
will give the identical impact strength compare to Rimdusit et al. (2012). Thus, for this
degradation study, 30 wt% of ABS will be choose to blend with 70 wt% of PVC. Although
using 30 wt°lo of ABS will not give the highest mechanical properties compare to 50 wt%
of ABS, the composition of 30 wt% of ABS is more economical to the highest
composition. Then, comparison between 15 to 30 wt°lo of ABS show that 30 wt°/o will
result in the highest mechanical properties. So, by choosing 30 wt°lo of ABS, it is the best
composition to use in term of material properties and economic scale.
Effect of repeated extrusion on the properties and durability of rigid PVC scrap
have been studied previously (Yarahmadi et al. , 2001). The PVC scrap has been extruded
for five times without adding new additives. The result shows that PVC scrap is suitable
for mechanical recycling for up to three times only. The fourth recycle show the decrease
in extrusion pressure cause by rheological breakdown under stress. Thus, based on the
5
© Universiti Teknikal Malaysia Melaka
Faculty of Manufacturing Engineering
THE DEGRADATION STUDY OF PVC/ABS AND
PVC/ABS/CARBON BLENDS DURING REPEATED EXTRUSION
ON MECHANICAL AND THERMAL PROPERTIES
Muhyiaddin Abdul Qadir bin Abu Bakar
Master of Manufacturing Engineering (Industrial Engineering)
2014
© Universiti Teknikal Malaysia Melaka
ｐｖｃＯａｂｓｒｏｾ＠
THE DEGRADATION STUDY OF PVC/ABS ａｾｄ＠
BLENDS DURING REPEATED ｅｘｔｒｌＧｓｉｏｾ＠
ON MECHANICAL AND THER'1AL PROPERTIES
MUHYIADDIN ABDUL QADIR BIN ABL' BAKAR
A thesis submitted
in fulfillment of the requirements for the degree of Master of
Manufacturing Engineering (Industrial Engineering)
Faculty of Manufacturing Engineering
UNIVERSITI TEKNIKAL MALAYSIA :WELAKA
2014
© Universiti Teknikal Malaysia Melaka
DECLARATION
I hereby, declared that this report entitled ' The Degradation Study of PVC/ABS and
PVC/ABS/Carbon Blends During Repeated Extrusion on Mechanical and Thennal Properties'
is the results of my own research except as cited in the references.
0
Signature
Name
: Muhyiaddin Abdul Qadir Bin Abu Bakar
Date
© Universiti Teknikal Malaysia Melaka
APPROVAL
I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms
of scope and quality for the award of Master of Manufacturing Engineering (Industrial
Engineering).
Signature
Supervisor Name
: Dr. Zaleha Binti Mustafa
Date
© Universiti Teknikal Malaysia Melaka
ABSTRACT
The degradation effects on numbers of extrusion of PVC/ABS and PVC/ABS/Carbon
blends to mechanical and thermal properties have been investigated. The composition of
PVC/ ABS blends was 80/20 wt% and PVC/ABS/Carbon was 73/23/7 wt°/o. The study has
been focused on ultimate tensile strength, strain at ultimate tensile, elastic modulus and
strain at faiJure for mechanical properties of the blends. Ultimate tensile strength, strain at
ultimate tensile and elastic modulus have been retained by both PVC blends due to the
presence of SAN phase from ABS that possess the complete retention with increasing
numbers of extrusion. On the other hand, the presence of butadiene rubber (BR) phase in
ABS increase the deformability of PVC blends which contributed to increase strain at
failure. Increased numbers of extrusion have refined the dispersion of carbon in the blends
and made stronger adhesion between carbon and the matrix that led to increase the strain at
failure of PVC/ABS/Carbon. Glass transition temperature (Tg) have been obtained using
differential scanning calorimetry (DSC) for thermal properties of the blends. The partial
miscibility between the components of the blends was concluded from two Tg obtained
from DSC test. Finally, a morphological study of the fracture surface has been completed
using scanning electron microscopy (SEM). The images from SEM justify the mechanical
properties of the PVC blends.
© Universiti Teknikal Malaysia Melaka
ABSTRAK
Satu kajian berkaitan kesan proses penolakan berterusan keatas campuran PVC/ABS dan
PVCIABS/Karbon telah dijalankan bagi melihat perubahan keatas sifat mekanikal dan
termal campuran. Komposisi bagi campuran PVC/ABS telah ditetapkan pada 80120 % dan
campuran PVC/ABS/Karban pada 7312317 %. Kajian ini akan memberi penekanan pada
kekuatan tegangan puncak, terikan pada tegangan puncak, modulus anjal dan terikan
putus bahan. Kekuatan tegangan puncak, terikan pada tegangan puncak dan modulus
anjal dapat dikekalkan oleh kedua-dua campuran berpunca daripada kehadiran fasa SAN
daripada ABS yang telah menghalang daripada berlakunya perubahan pada sifat bahan
walaupun proses penolakan berterusan dilakukan berulang kali. Sela in itu, kehadiran fasa
getah butadiene (BR) dalam ABS telah meningkatkan kadar perubahan bentuk bahan
campuran PVC yang secara tidak langsung telah meningkatkan sifat terikan putus.
Penambahan proses penolakan berterusan telah mensebatikan unsur karbon dalam
campuran PVC yang menyebabkan lekatan antara unsur karbon dan unsur matrix
bertambah baik. Keadaan ini menyebabkan peningkatan pada sifat terikan putus bahan
campuran PVC. Suhu perubahan gelas (Ig) telah direkodkan menggunakan mesin
pengimbas perubahan kalori (DSC) untuk sifat termal bahan campuran. Dua Tg telah
didapati pada setiap sampel yang mana telah menunjukkan bahawa bahan campuran PVC
ini adalah bersifat separuh terlarut campur.. Bagi mengesahkan sifat mekanikal bahan
yang telah diperolehi tadi, maka akhirnya ujian pengimbasan electron mikroskop (SEM)
telah dijalankan.
ii
© Universiti Teknikal Malaysia Melaka
ACKNOWLEDGEMENTS
First and foremost, I would like to take this opportunity to express my sincere
acknowledgement to my supervisor Dr. Zaleha Mustafa from the Faculty of Manufacturing
Engineering Universiti Teknikal Malaysia Melaka (UTeM) for her essential supervision,
support and encouragement towards the completion of this Master Project 2.
Particularly, I would also like to express my deepest gratitude to Mr. Azhar and Mr. Hairul
Hisham, the technicians from material laboratory Faculty of Manufacturing Engineering,
for their assistance and efforts in the lab and analysis works.
Special thanks to all my peers, my mother, beloved father and siblings for their moral
support in completing this Master Project 2. Lastly, thank you to everyone whom had been
to the crucial parts of realization of this project.
iii
© Universiti Teknikal Malaysia Melaka
TABLE OF CONTENTS
CHAPTER
TITLE
DECLARATION
ABSTRACT
ABSTRAK
ACKNOWLEDGEMENTS
TABLE OF CONTENTS
LIST OF TABLES
LIST OF FIGURES
LIST OF ABBREVEATIONS
LIST OF APPENDICES
1
2
3
INTRODUCTION
1.1 Background
1.2 Problem Statements
1.3 Research Objectives
1.4 Scope of study
LITERATURE REVIEW
2.1
Thermoplastics and thermosets
2.2
Polymer Degradation
2.2.1 Thermal Degradation
2.2.2 Photo-degradation
2.2.3 Oxidation or aging degradation
2.3
Polyvinyl Chloride (PVC)
2.3.1 Mechanical Properties
2.3.2 Thermal Properties
2.3.3 Advantages and Disadvantages
2.3.4 Rigid PVC for Extrusion
2.4
Acrylonitrile Butadiene Styrene (ABS)
2.4.1 Properties
2.4.2 Mechanical Properties
2.4.3 Thermal Properties
2.4.4 Ultraviolet Resistance
2.4.5 Preheating and Pre-drying
2.4.6 Advantages and Disadvantages
2.5
Polymer Blends
2.5.1 PVC/PS and PVC/ABS Blends
2.6
Carbon
2.7
Extrusion Process
2.7.1 Process Parameters
2.8
Repeated Extrusion
2.9
Fracture Morphology of Amorphous Polymer
2.10 Design of Experiments (DOE)
2.11 Summary
METHODOLOGY
3.1
Introduction
3.2
Design of Experiments (DOE)
3.3
Flow Chart
iv
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PAGE
ii
iii
iv
vi
vii
xii
xv
1
3
7
7
9
9
10
11
13
15
16
19
21
22
23
24
25
27
28
29
29
31
31
37
39
39
41
47
51
53
54
54
56
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4
5
Materials
Blends Preparation
Extrusion Process
Samples Preparation
Mechanical Properties
Thermal Properties
Morphology
RESULT AND DISCUSSION
4.1
Introduction
4.2
Mechanical Properties
4.2.1 Analysis of variance (ANOVA)
4.2.2 Ultimate Tensile Strength
4.2.3 Strain at Ultimate Tensile Strength
4.2.4 Elastic Modulus
4.2.5 Strain at Failure
4.3
Thermal properties
4.4
Fracture Morphology
CONCLUSION & RECOMMENDATION
5.1
Conclusion
5.2
Recommendation
REFERENCES
APPENDICES
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57
58
58
60
61
63
64
66
66
68
71
73
74
75
77
81
91
93
94
104
LIST OFT ABLES
TITLE
TABLE
PAGE
2.1
Mechanical & thermal properties of PVC
18
3.1
Design of experiment (DOE)
55
3.2
Properties of PVC
57
3.3
Properties of ABS
57
3.4
Properties of Carbon
57
3.5
Blend composition
58
3.6
Temperature zones of extrusion profile
58
3.7
Numbers of specimens required
60
Specification of Universal Testing Machine 5kN (Computer Servo
62
3.8
Control)
3.9
Zeiss Stemi 2000 Stereomicroscope specification
65
3.10
Zeiss EVO 50 XVP Electron scanning microscope specification
65
Effect of numbers of extrusion to the mechanical properties of PVC
67
4.1
4.2
and PVC blends
Effect of numbers of extrusion to the glass transition temperature of
77
PVC, ABS and PVC blends
4.3
Composition of PVC and ABS at PVC and SAN-rich phase
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© Universiti Teknikal Malaysia Melaka
80
LIST OF FIGURES
FIGURE
2.l
TITLE
Thermal dehydrochlorination of PVC. C: Carbon. H: Hydrogen. Cl :
Chlorine.
2.2
ｾＺ＠
PAGE
11
Heat. x,y: Integers
Scanning Electron Micrograph for (a)-(i) unexposed film of only
12
PVC (a)-(ii) only PVC film exposed to solar radiation (a)-(iii) only
PVC film exposed to artificial UV radiation. (b)-(i) Unexposed
composite film of PVC- ZnO (b)-(ii) PVC- ZnO composite film
exposed to solar radiation (b)-(iii) PVC- ZnO composite film exposed
to artificial UV radiation
2.3
Laser microscopic image of the fading section around the surface
13
after weathering test: (a) 0 h (the obvious inorganic particles are
pointed by arrows), and (b) 3000 h (the obvious voids are pointed by
arrows)
2.4
Laser microscopic image of the section around the surface after
14
thermal aging test: (a) 0 h, and (b) 240 h. The obvious inorganic
particles are pointed by arrows
2.5
Molecular structure for (a) vinyl chloride and (b) polyvinyl chloride,
15
PVC
2.6
Dependence of tensile strength (crM) of the extrudate obtained from
17
the mixture of A/B (0 % gel/I 00% gel) granulated products on the
processing temperature (T): 1- 0/ 100 % gel; 2- 25/75 % gel; 3- 50/50
% gel; 4- 75/25 % gel; 5- 100/0 % gel
2.7
Dependence of relative elongation at failure (c8 ) of the extrudate
17
obtained from the mixture of A/B (0% gel/ 100% gel) granulated
products on the processing temperature (T): 1- 0/100 % gel; 2- 25/75
% gel; 3- 50/50 % gel; 4- 75/25 % gel; 5- 100/0 % gel
2.8
DSC Curve of uPVC Gelation Test
vii
© Universiti Teknikal Malaysia Melaka
20
2.9
Molecular structure of ABS monomer
23
2.10
Molecular structure of ABS
24
2.11
The change in Izod impact strength with the increase of injection
25
cycles
2.12
The change in stress at yield point with the increase of injection
26
cycles
2.13
External surface of ABS sewer pipe after UV exposure
28
2.14
Notched impact strength of composites as a function of nano-CaC03
33
content
2.15
Yield strength and elongation at failure of the composites as a
33
function of nano-CaC0 3 content
2.16
Impact strength as a function of the PVC:ABS ratio
34
2.17
Impact properties of the PVC/ ABS blends at various mass blending
35
ratios
2.18
Scanning electron micrographs of tensile-tested PVC/ ABS (70:30)
36
blend
2.19
TE M images; left=l5nm CB sample " good dispersion"; right= l5nm
37
CB sample " bad dispersion"
2.20
The relation between the Modulus of elasticity of HDPE sample with
38
weight fraction of Ti02-C.B.fillers at different wt.% of C.B and
constant Ti02 content (15% wt) and. at different wt.% of Ti02and
constant C.B content
2.21
Mass throughput at screw speeds of 50 and 90 rpm and Energy
40
consumption at screw speeds of 50 and 90 rpm
2.22
The extrusion pressure and elongation at failure, as a function of
41
number of extrusions
2.23
The elongation at failure for ABS vs the number of cycles in the
extrusion series, the series involving ageing steps of 72 h at 90°C and
viii
© Universiti Teknikal Malaysia Melaka
42
the combined extrusion and ageing series. The data point at 0 cycles
represent elongation at failure for samples of ABS after the first
extrusion
2.24
Tensile strength of ABS subjected to multiple reprocessing
44
2.25
The effect of the number of injection mouldings of ABS on tensile
44
strength (1) and tensile stress at failure (2)
2.26
Elongation at failure of ABS subjected to multiple reprocessing
45
2.27
The effect of the number of injection mouldings of ABS on tensile
45
strain at ultimate tensile (1) and tensile strain at failure (2)
2.28
The effect of the number of injection mouldings of ABS on modulus
46
of elasticity
2.29
The effect of the number of injection mouldings of PC on tensile
46
strength (I) and tensile stress at failure (2)
2.30
Fracture surface of PS in SEM: a, overview with brittle fracture
48
edges; b, larger magnification of ruptured crazes with domain-like
hills, revealing broken and relaxed craze fibrils
2.31
Scheme
showing
differences
between
homogeneous
(a)
and
48
fibrillated crazes (b) in relation to the entanglement network: top,
view as in electron micrographs; bottom, entanglement network with
stretched meshes. a, Dense pattern of small stretched meshes in
homogeneous crazes; b, coarse pattern with voiding and fibrillation in
large meshes in fibrillated crazes
2.32
SEM micrographs of ABS in shear deformation fracture level
49
2.33
Shear deformation of 100 wt% ABS
50
2.34
'Black Box' Process Model Schematic
51
2.35
Half-Normal Probability Plot
52
2.36
Normal Probability Plot
52
ix
© Universiti Teknikal Malaysia Melaka
3.1
Design schematic for DOE of the study
55
3.2
Flow chart of the experiments
56
3.3
ASTM D638-I-mm units
60
3.4
GOTECH Universal Testing Machine
61
3.5
Perkin Elmer DSC 4000
63
3.6
Zeiss Stemi 2000 Stereomicroscope
64
3.7
Zeiss EVO 50 XVP Scanning Electron Microscope
65
4.1
Half normal% probability graph; (a) Ultimate tensile
ｳｴｲ･ｮｧｨ
ｾ＠
(b)
69
Strain at ultimate tensile, (c) Elastic Modulus, (d) Strain at failure
4.2
Normal probability plot ofresidual; (a) Ultimate tensile
ｳｴｲ･ｮｾ＠
(b)
70
Strain at Ultimate Tensile, (c) Elastic Modulus, (d) Strain at failure
4.3
Interaction plot between materials and number of extrusion; effect of
72
numbers of extrusion to ultimate tensile strength.
4.4
Interaction plot between materials and number of extrusion; effect of
73
numbers of extrusion to strain at ultimate tensile
4.5
Interaction plot between materials and number of extrusion; effect of
74
numbers of extrusion to elastic modulus.
4.6
Interaction plot between materials and number of extrusion; (a) effect
75
of different materials to strain at failure, (b) effect of number of
extrusions to strain at failure.
4.7
DSC thermograms of PVC with different numbers of extrusion
78
4.8
DSC thermograms of PVC/ABS 70/30 wt°/o with different numbers
78
of extrusion
4.9
DSC thennograms of PVC/ABS/Carbon 70/23/7 wt°/o with different
79
numbers of extrusion
4.10
Optical and Scanning electron micrographs of tensile tested 1st
81
extrusion PVC (a) PVC drawing at the crack path;(b) pores at the
crack ;(c) --{d) crack path propagation
4.11
Scanning electron micrographs of tensile tested 2°d extrusion PVC.
(a) optical micrograph on the start of crack formation path;(b) jagged
82
fracture surface;(c)-(d) smooth fracture surface.
4.12
Scanning electron micrographs of tensile tested 3rd extrusion PVC.
(a) shear deformation region;(b)-(c) fibrillated deformation region;(d)
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© Universiti Teknikal Malaysia Melaka
83
crack path propagation.
4.13
Scanning electron micrographs of tensile tested
wt% PVC/ABS blend.
1 st
extrusion 70/30
(a) jelly fish surface;(b)
84
coexisted
deformation;(c) crack from the top view; (d) crack from side view
4.14
Scanning electron micrographs of tensile tested 2°d extrusion 70/30
wt% PVC/ABS
85
blend. (a) microvoids on shear deformation
surface;(b) coexisted deformation;( c) shear deformation region; (d)
fibril from side view
4.15
Scanning electron micrographs of tensile tested 3rd extrusion 70/30
86
wt% PVC/ABS blend. (a) fibrillated deformation surface;(b) -{c)
shear deformation or homogeneous region;( d) crack from side view
4.16
Scanning electron micrographs of tensile tested
1 st
extrusion 70/23/7
87
wt% PVC/ABS/Carbon blend. (a) shear deformation surface;(b)
relaxed craze fibril ;(c) not homogeneous dispersion of carbon;(d)
crack at with massive shear deformation
4.17
Tensile fracture surface of 70/23/7 wt% PVC/ABS/Carbon blends
88
after 2rd extrusion. (a) shear or homogeneous deformation surface;(b)
coexisted deformation surface;(c) fibrillated deformation surface;(d)
dispersion of carbon
4.18
Tensile fracture surface of 70/23/7 wt% PVC/ ABS/Carbon blend
after 3rd cycle of extrusion process.(a) brittle region (b) homogeneous
region, (c) crack, (d) more refine dispersion of carbon.
xi
© Universiti Teknikal Malaysia Melaka
89
LIST OF ABBREVEATIONS
ABS
Acrylonitrile butadiene styrene
ASA
Acrylonitrile Styrene Acrylate
AMS-ABS
a-methylstyrene-acrylonitrile- butadiene-styrene copolymer
ANOVA
Analysis of Variances
ASTM
American Society for Testing and Materials
V-0
Burning stops within 60 seconds on a vertical specimen
BR
Butadiene rubber
DOE
Design of Experiments
CaC03
Calcium carbonate
CB
Carbon black
oc
Degree of centigrade
DSC
Differential scanning calorimetry
OMA
Dynamic Mechanical Analysis
CPE
Chlorinated polyethylene
Elongation at failure
EVA
Ethylene vinyl acetate
EPDM
Ethylene propylene diene monomer
ft
Foot
GPC
Gel permeation chromatography
Tg
Glass transition temperature
HCI
Hydrogen chloride
HDT
Heat distortion temperature
HOPE
High-density polyethylene
h
hour
in
Inch
J
Joule
kg
Kilogram
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© Universiti Teknikal Malaysia Melaka
LDPE
Low density polyethylene
LOI
Loss on ignition
MAH
Maleic anhydride grafted
MAStVA
Maleic anhydride-styrene-vinyl acetate
Wt%
Mass fraction
m
Meter
Tm
Melting temperature
mm
Milimeter
MPa
Megapascal
NBR
Nitrile butadiene rubber
Tonset,m
Onset melting temperature
%
Percent
PC
Polycarbonate
PMMA
Poly(methyl methacrylate)
pp
Polypropylene
PPE
Polyphenyl ethers
PVC
Polyvinyl chloride
PS
Polystyrene
lbs
Pound
psi
pound per square inch
RH
Relative humidity
rpm
Revolutions per minute
T
Temperature
CTM
Tensile strength
Ti02
Titanium dioxide
K-value
Thermal conductivity
TGA
Thermogravimetric
TP
Thermoplastic
TS
Thermo set
TEM
Transmission electron microscopy
SEM
Scanning electron microscope
SD
Standard deviation
SAN
Styrene Acrylonitrile
xiii
© Universiti Teknikal Malaysia Melaka
SMA
Styrene-maleic anhydride
UL94
Standard for Safety of Flammability of Plastic Materials
UV
Ultraviolet
VCM
Vinyl Chloride Monomer
XRF
X-ray Fluorescence
w
Weight fraction
ZnO
Zinc Oxide
xiv
© Universiti Teknikal Malaysia Melaka
LIST OF APPENDICES
TITLE
NO
A
Page
104
Overall ANOV A Report
xv
© Universiti Teknikal Malaysia Melaka
CHAPTER!
INTRODUCTION
1.1
Background
Plastics can be divided into two groups which are thermoplastic (TP) and thermoset
(TS). Thermoplastic is the type of plastic that can be repeatedly softened by heating and
then solidified by cooling. Molecules
iri
a thermoplastic are held together by relatively
weak intermolecular forces. Thermoplastic can be processed several times and makes these
kinds of plastics suitable for recycling. Thermosets in a soft solid or viscous state that
changes irreversibly into an infusible, insoluble polymer network by curing. Curing can be
induced by the action of heat or suitable radiation or both. A cured thermosetting polymer
is called a thermoset.
Polyvinyl chloride (PVC) is a thermoplastic polymer. PVC is primarily an
amorphous material with good durability, fire retardant, oil and chemical resistant and
good mechanical properties. Many commercial polyvinyl chloride (PVC) resins contain
crystalline regions ranging from 5 to I 0 % of the polymer. The polymer will remain intact
at temperatures well over 200 °C. The region of crystallinity with relatively narrow
molecular weight distribution will help impart superior melt strength during extrusion.
Another unique characteristic of polyvinyl chloride (PVC) is the amorphous nature of the
polymer promotes cost effective fabrication of clear articles in thickness exceeding 0.25 in
(lOmm) if proper addictive selection used (Grossman, 2008).
Polyvinyl chloride (PVC) contains approximately 57 % chlorine by weight. The
condition of the polymer will creates strongly polar region and make it compatible with a
1
© Universiti Teknikal Malaysia Melaka
wide range of additives. No other commercial polymer can have its properties modified in
so many ways compare to polyvinyl chloride (PVC). Beside of that, the chlorine in
polyvinyl chloride (PVC) will also make the polymer flame resistance.
PVC has been use in wide range of short life and long life product application. In
short life product, PVC have been processed in packaging material use in food, cleansing
materials, textile, beverage packaging bottles and medical devices. In long life product,
PVC have been processes into pipes, window frames, cable insulation, floors coverings
and roofing sheets (Sadat-Shojai and Bakhshandeh, 2011).
2
© Universiti Teknikal Malaysia Melaka
1.2
Problem Statements
Every product has specific cycle time. There is a time when the product will come
to their end life and the product need to be properly disposed. PVC with a wide range of
products, their waste will increase with time. Thus will become a problem to the
community. Today, PVC waste is dispose in landfill. However, using landfill to cater the
problem is not a good solution because the area required for landfilling will increase with
increasing of the waste. Beside of that, using landfilling to dispose PVC waste have
potential environmental hazard because of the chlorine content of the polymer.
Another route to solve the increment of PVC waste is by recycle the PVC waste
into another product. Thus, recycling of the PVC has gain interest for researcher in order to
produce secondary materials (Sadat-Shojai and Bakhshandeh, 2011). However, recycle the
PVC into similar or another product is not a straight path. Recycle PVC showed to have
inferior mechanical properties (Yarahmadi et al., 2001). The recycle PVC with low
mechanical properties however can be process into a low strength requirement type of
product with cost conscious production. But, if the recycle PVC need to be use in another
requirement type of products, the molecule properties of the material need to be alter.
One of the most popular methods to retain and increase the properties of the
material is by blending the polymer with another polymer. Polymer blending has become
an important field in polymer research. ln this research the target was to reduce the
polymer waste problem by blending the PVC with other type of polymer and make sure
that the recycle blends polymer still retains an identical properties compare to the first
cycle of the blends. With identical properties of the blends compare to the virgin and the
recycle of the virgin, it will make the blends as an ideal replacement material to be used for
consumer products. Then, by showing a slightly decrease in properties after a few recycle
compare to the copolymer that show greater decrease in properties, the polymers blends
3
© Universiti Teknikal Malaysia Melaka
will fulfil the purpose to retain the properties of the material and can be used for several
times in processing. It will give a huge profit for recycle industries because the scrap from
the blends can be recycle to be made into the same or different product that meet the
requirement base on their properties whereas the recycle from the copolymer cannot
sustain the same properties.
Beside of improving physical properties of the material, polymer blends will also
benefit in low investment cost in a new material design. In this case, a cheaper material
like PVC will be dilute with expensive polymer material in hope to retaining some of the
high performance properties. The blends maybe homogeneous (true thermodynamic
miscibility of components) or heterogeneous (phase-separated). In heterogeneous blends,
components maybe thermodynamically immiscible but mechanically compatible (Elias,
2003). Many researches have blend PVC with other polymer materials such as
PVC/PMMA, PVC/NBR, PVC/EVA and PVC/CPE (Grossman, 2008). Thus, the objective
to minimize the cost for a new material design with improves material properties can be
achieved.
Polystyrene (PS) is amorphous region material with good impact resistance high
heat resistance. In theory, blending PVC with PS will improve thermal and mechanical
properties of the material. But, does the properties can be retain if the blends were recycles
for several times? The assumption can be made that the recycle of PVC/PS blends will
give the identical outcome with slightly reduce number compare to the first cycle. Another
famous amorphous region material is acrylonitrile butadiene styrene (ABS) with good
impact resistance, toughness and weather ability. In theory, blends PVC with ABS will
improve impact resistance, toughness and weather ability of the material (Rimdusit et al. ,
2012). But, does the properties can be retain if the blends were recycles for several times?
Same as PVC/PS blends, assumption can be made that the recycle of PVC/ABS blends will
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give the identical outcome with slightly reduce number compare to the first cycle. There
are very limited knowledge about the properties either PVC/PS or PVC/ABS biends when
there were recycles for several times.
Blends of polyvinyl chloride (PVC) with a-methylstyrene-acrylonitrile- butadienestyrene copolymer (AMS-ABS) show a single glass transition temperature (Tg) when
observed by differential scanning calorimetry (DSC). This result indicates that PVC is
miscible with AMS-ABS (Zhang et al. , 2013). The research suggest that the most
interesting area for further investigation is the region containing 15 - 30 wt% of AMSABS because within these compositions, the heat distortion temperature (HDT) and the
impact strength have improved effectively without losses in tensile and flexural properties.
The impact strength show gradually increase when the PVC/ABS blends below 30 wt% of
ABS content and the drastic increase observed when the ABS content range from 30 to 50
wt% (Rimdusit et al. , 2012). Pavan et al. (1980) show that 30 wt% of PVC/ABS blends
will give the identical impact strength compare to Rimdusit et al. (2012). Thus, for this
degradation study, 30 wt% of ABS will be choose to blend with 70 wt% of PVC. Although
using 30 wt°lo of ABS will not give the highest mechanical properties compare to 50 wt%
of ABS, the composition of 30 wt% of ABS is more economical to the highest
composition. Then, comparison between 15 to 30 wt°lo of ABS show that 30 wt°/o will
result in the highest mechanical properties. So, by choosing 30 wt°lo of ABS, it is the best
composition to use in term of material properties and economic scale.
Effect of repeated extrusion on the properties and durability of rigid PVC scrap
have been studied previously (Yarahmadi et al. , 2001). The PVC scrap has been extruded
for five times without adding new additives. The result shows that PVC scrap is suitable
for mechanical recycling for up to three times only. The fourth recycle show the decrease
in extrusion pressure cause by rheological breakdown under stress. Thus, based on the
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